Very good idea !

Thank you for your comment Kayte !

I really don't think it would support or promote private topics, even if I understand your point of view.

Yes, the place would be reserved for some people only. But anyone in those people could come in a topic, like anywhere else.

In Hogwarts (I mean in the books or the movies), no one has the access except Capitains or Prefects, and nobody cries about it. Harry himself has no idea of this room's existence, until Cedric gives him the password to get in.

Of course someone which arrived yesterday can't afford access in the bathroom, but I really think that a lot of student would give it to others and that way it would be really more realistic.